Field
The invention relates to a method for displaying video endoscopic image data of a video endoscope having at least one lateral viewing direction, wherein at least one objective which is movable relative to an image sensor about the longitudinal axis of a shaft of the video endoscope and has at least one lateral viewing direction is arranged on the distal end of the shaft wherein the viewing direction is changed over from a first viewing direction to a second viewing direction on account of a viewing direction changeover command.
The invention furthermore relates to a video endoscopy system comprising a video endoscope, an image processing unit and an image reproduction device, wherein the video endoscope has an image sensor and at least one objective which is arranged on the distal end of an endoscope shaft and is movable relative to the image sensor about the longitudinal axis of the shaft and has at least one lateral viewing direction, wherein the viewing direction can be changed over from a first viewing direction to a second viewing direction on account of a viewing direction changeover command. Finally, the invention relates to a software program product comprising program code means.
Prior Art
In the scope of the present invention, a video endoscope is understood to be an endoscope in connection with at least one image sensor, which is designed to capture a video recording, independently of whether the image sensor is disposed distally in the endoscope shaft, proximally in a handle, or externally in a camera head, which can be attached to an ocular in the proximal region of the endoscope, thus on the side of a surgeon.
The term image direction, also called “direction of view” (DOV), relates to the lateral image or reverse image deviating from the longitudinal axis of the endoscope and is represented as a polar angle, wherein a viewing angle of 0° means a direct view in the longitudinal direction of the endoscope shaft, while 90°, for example, designates an image direction which deviates at a right angle from the direct view. The present invention relates to endoscopes with which the azimuth angle of the viewing direction, thus the angle of the rotation of the viewing direction about the longitudinal axis of the endoscope, can be changed.
Along with endoscopes having a single lateral viewing objective at the distal end, endoscopes are also known having several objectives which are aligned in discrete viewing directions, and which are designed changeable between the viewing directions. Typical pairs of viewing directions with endoscopes having directions of view which can be changed over, in the sense of the polar angle, for example, 0° and 30°, 0° and 45°, 12° and 70° or 30° and 80°. At least one viewing direction of the pair is therefore a lateral viewing direction. Such objectives having two discrete viewing directions permit the surgeon with a thusly equipped endoscope to be able to view in the different viewing directions as desired. In the scope of the present invention, this adds to the changeability of the azimuth angle of the direction of view.
The present applicant's patent application DE 10 2009 020 262 A1 discloses an endoscope having two viewing directions. The associated objectives are disposed in the distal end region of an endoscope shaft and receive the light coming from their respective field of view, in order to further conduct the light to an image sensor or to an ocular. It is possible to change over between the two viewing directions. A prism is disposed in an intersection of the two optical paths.
The changeover between the viewing directions occurs by removing or introducing a mirror into a gap between the first optical path and the prism. When no mirror is introduced into the gap, the light in the first optical path enters into the prism unimpeded, and through the prism, and arrives at the ocular or at an image sensor. The light of the second optical path is reflected at a first boundary surface of the prism, but in the absence of total reflection, exits at a second boundary surface from the prism in a direction which does not lead to the ocular or to the image sensor. If a mirror is introduced into the gap, the light in the first optical path is blocked, whereas the light of the second optical path is now reflected a second time, and thereby is further conducted laterally to the ocular or to the image sensor.
Additional objectives having two viewing directions are disclosed in the documents EP 0 363 118 B1 and EP 0 347 140 B1.
According to the document EP 0 363 118 B1, for each viewing direction a distal objective part is provided that respectively directs the output optical path in one of two parallel output axes. A proximal objective part can be pivoted together with the image conductor leading further from the objective part through the shaft of the endoscope such that in two pivot locations, the objective part is aligned onto the one or the other of the two output axes.
According to the document EP 0 347 140 B1, an endoscope objective has two distal objective parts for two different viewing directions, and a common proximal objective part. Polarization filters having different fixed polarization units are disposed in the two distal objective parts, and a polarization filter having an adjustable polarization unit is disposed in the proximal objective part. Thus, it is possible to change-over between the two viewing directions. With a simpler design, the image brightness is reduced compared to the other designs.
The document EP 2 147 631 A1 relates to an endoscope having an objective and a swing prism, by means of which the lateral viewing direction is altered.
Furthermore, from the document US 2006/0293565 A1 an endoscope is known comprising an objective that is disposed on a platform in the distal tip of the endoscope, the platform being able to be tipped in one direction or different directions, and is moved by tipping the platform in different directions.
For the orientation thereof in the operative field, which is extremely important with examinations and with surgery, the surgeon depends on his perception of space. It can occur, even with endoscopes having a single lateral viewing direction, that the surgeon in the course of an endoscopic examination or endoscopic procedure loses his orientation after a series of rotations or movements, especially when a part of the endoscope which is important for the orientation, is held by an assistant.
With the mentioned endoscopes comprising viewing directions that can be changed-over there is the fact that the viewing direction is changed-over in discrete steps, so that the displayed objects abruptly change their position. Thus, the challenge for the surgeon is to receive two very different images from one moment to the next that represent different sections of the current operative field. The switching can therefore have a disorienting effect. Because the images are typically displayed on a fixed image screen, moreover the displayed image does not necessarily correspond to the orientation of the endoscope in space and in the operative field.